Division of Reproductive Health
National Center for Chronic Disease Prevention and Health
Promotion

Abstract
Problem/Condition: The Healthy People 2000: National Health
Promotion and Disease Prevention Objectives specifies goals of no
more than 3.3 maternal deaths per 100,000 live births overall and
no more than 5.0 maternal deaths per 100,000 live births among
black women; as of 1990, these goals had not been met. In
addition, race-specific differences between black women and white
women persist in the risk for pregnancy-related death.
Reporting Period Covered: This report summarizes surveillance data
for pregnancy-related deaths in the United States for 1987-1990.
Description of System: The National Pregnancy Mortality
Surveillance System was initiated in 1988 by CDC in collaboration
with the CDC/American College of Obstetricians and Gynecologists
Maternal Mortality Study Group. Health departments in the 50
states, the District of Columbia, and New York City provided CDC
with copies of death certificates and available linked outcome
records (i.e., birth certificates or fetal death records) of all
identified pregnancy-related deaths.
Results: During 1987-1990, 1,459 deaths were determined to be
pregnancy-related. The overall pregnancy-related mortality ratio
was 9.2 deaths per 100,000 live births. The pregnancy-related
mortality ratio for black women was consistently higher than for
white women for every risk factor examined by race. The disparity
between pregnancy-related mortality ratios for black women and
white women increased from 3.4 times greater in 1987 to 4.1 times
greater in 1990. Older women, particularly women aged greater than
or equal to 35 years, were at increased risk for pregnancy-related
death. The gestational age-adjusted risk for pregnancy-related
death was 7.7 times higher for women who received no prenatal care
than for women who received "adequate" prenatal care. The
distribution of the causes of death differed depending on the
pregnancy outcome; for women who died following a live birth
(i.e., 55% of the deaths), the leading causes of death were
pregnancy-induced hypertension complications, pulmonary embolism,
and hemorrhage.
Interpretation: Pregnancy-related mortality ratios for black women
continued, as noted in previously published surveillance reports,
to be three to four times higher than those for white women. The
risk factors evaluated in this analysis confirmed the disparity in
pregnancy-related mortality between white women and black women,
but the reason(s) for this difference could not be determined from
the available information.
Actions Taken: Continued surveillance and additional studies
should be conducted to assess the magnitude of pregnancy-related
mortality, to identify those differences that contribute to the
continuing race-specific disparity in pregnancy-related mortality,
and to provide information that policy makers can use to develop
effective strategies to prevent pregnancy-related mortality for
all women.

INTRODUCTION

The Healthy People 2000: National Health Promotion and
Disease Prevention Objectives for the United States listed
maternal mortality as a priority area for improvement, including
specific goals of no more than 3.3 maternal deaths per 100,000
live births overall, and no more than 5.0 maternal deaths per
100,000 live births among black women (1). These goals have not
yet been achieved. Moreover, there have been continuing
disparities in the risk for pregnancy-related death between black
women and white women (2). The pregnancy-related mortality ratios
(i.e., pregnancy-related deaths per 100,000 live births) for black
women are more than three times higher than for white women (3).
The results of previous research have indicated that most
pregnancy-related deaths are preventable (4-6). A reduction in
pregnancy-related deaths continues to be a primary public health
objective (1,7).

To further understand and evaluate the risk factors for and
leading causes of pregnancy-related death, the National Pregnancy
Mortality Surveillance System was initiated in 1988 by CDC's
Division of Reproductive Health, National Center for Chronic
Disease Prevention and Health Promotion, in collaboration with the
CDC/American College of Obstetricians and Gynecologists (ACOG)
Maternal Mortality Study Group (8). This system provides ongoing
surveillance of all pregnancy-related deaths identified through
the individual state systems and through other sources of
reporting. This report summarizes the analysis of identified
pregnancy-related deaths in the United States from 1987 through
1990 (i.e., the year for which the most recent information is
available).

METHODS

Health departments in the 50 states, the District of
Columbia, New York City, and Puerto Rico provided CDC with copies
of death certificates and available matched pregnancy-outcome
records (i.e., birth certificates or fetal death records) for all
identified pregnancy-related deaths during 1987-1990.

A woman's death was classified as pregnancy-related if it
occurred during pregnancy or within 1 year after the pregnancy and
resulted from a) complications of the pregnancy, b) a chain of
events that was initiated by the pregnancy, or c) the aggravation
of an unrelated condition by the physiologic or pharmacologic
effects of the pregnancy (8). A woman's death was considered to be
a potential pregnancy-related death if a) a pregnancy check box
was marked on the death certificate, b) the death certificate
otherwise indicated that the woman was pregnant at the time of
death, or c) the woman's death certificate was matched with a
birth certificate or fetal death record for a delivery that
occurred within 1 year before the woman's death. Information
concerning each death was reviewed by experienced clinical
epidemiologists to determine whether it was a pregnancy-related
death.

Deaths were classified using a system designed in
collaboration with members of the CDC/ACOG Maternal Mortality
Study Group (8). Several of the variables stated on the death
certificate that were examined included the immediate and
underlying causes of death, any associated obstetrical conditions
or complications, and the outcome of pregnancy. Information was
obtained from death certificates (including notes written on the
margins of death certificates), maternal mortality review
committee reports and autopsy reports, and matched birth and fetal
death certificates.

Pregnancy-related mortality ratios were calculated by using
live-birth data obtained from the 1987-1990 national natality
files compiled by CDC's National Center for Health Statistics
(9-12).
Although data regarding pregnancy-related deaths in Puerto
Rico were available, published natality data included only the
births that occurred in the 50 states, the District of Columbia,
and New York City; therefore, pregnancy-related deaths in Puerto
Rico were not included in this analysis. Cornfield's method was
used to calculate risk ratios with 95% confidence intervals (13).
To control for the effects of age, pregnancy-related mortality
ratios for marital status were age-adjusted by direct
standardization (14). The standard population comprised all women
who had a live birth during 1987-1990 (9-12).

Matched outcome certificates (i.e., birth certificates and
fetal death certificates) were available for most women who
delivered a live-born or stillborn infant. These outcome
certificates provided data not available on the death certificate.
No outcome certificates were available for women who had an
ectopic pregnancy, women who had an abortion (i.e., either
spontaneous or induced), and women who died before delivery (i.e.,
"undelivered").

The women's ages were grouped into standard 5-year intervals.
Women aged 40-49 years were included in a single group, greater
than or equal to 40 years. For the analysis of race, women were
classified as white, black, or "other." Other races included
Asian/Pacific Islander, American Indian/Alaskan Native, and those
reported as "other." Because of the small number of women in the
"other" category, most analyses by race were limited to white
women and black women. Hispanic women were classified by their
reported racial group. For both the numerator and denominator of
pregnancy-related mortality ratios, race was defined as the race
of the mother.

The risk for pregnancy-related death by years of education
was determined from information on matched outcome certificates
for women whose pregnancy outcome was a live birth or a
stillbirth. The analysis of education was further restricted to
women aged greater than or equal to 20 years, an age by which most
women would have had the opportunity to graduate from high school.
The state of Washington did not report education on birth
certificates during the 4-year surveillance period, and three
other states -- California, New York (excluding New York City), and
Texas -- did not report education on the birth certificate during
some years of the surveillance period. Women who died in those
four states during the specific years when education was not
reported were excluded from the analysis of education.

Information concerning the adequacy of prenatal care was
limited to women who delivered a live-born infant, because the
information about prenatal care that was recorded on fetal death
certificates was insufficient for analysis. No information
regarding prenatal care was available for women who had
pregnancies with ectopic or abortive (spontaneous or induced)
outcomes or who were undelivered at the time of death. Deaths that
occurred in California during 1987-1988 also were excluded from
the analysis of adequacy of prenatal care because all three
components necessary to calculate prenatal care adequacy (i.e.,
gestational age, the month prenatal care began, and the number of
prenatal visits) were not reported consistently for those years.

The level of prenatal care was assessed by using a
modification of the adequacy of prenatal care use (APCU) index
developed by Kotelchuck (15). The APCU index measures the adequacy
of prenatal care by a) the timing of the first prenatal visit and
b) the appropriateness of the number of visits based on
gestational age (i.e., at the first prenatal visit and at
delivery). The modified index used for the purposes of this report
classified the level of prenatal care into one of the following
four categories (Table_1B):

This index differs from the APCU index in that the
"intermediate" category of prenatal care described by Kotelchuck
was combined with the category for "inadequate" care, because both
levels represented less than adequate prenatal care (15). A
category also was included for women who received no prenatal
care.

To control for the confounding effect of gestational age,
direct standardization (14) was used to calculate a gestational
age-adjusted rate for adequacy of prenatal care. The standard
population was based on the distribution of gestational age (in
weeks) for women whose prenatal care was "adequate" and who died
following a live birth. A gestational age-adjusted rate for the
adequacy of prenatal care by race could not be calculated because
of the small number of deaths and the large proportion of unknown
values for some categories.

The relationship between the size of the delivery hospital
and pregnancy-related mortality was assessed by using the size of
the hospital obstetric service (in terms of the number of live
births per year {American Hospital Association, unpublished data})
as the determinant of hospital size. The hospital size groups were
as follows: less than 300, 300-999, 1,000-1,999, 2,000-2,999, and
greater than or equal to 3,000 live births per year. The analysis
of hospital size was limited to women who died following a live
birth or a stillbirth. If a matched outcome record was unavailable
for a woman, then the size of the hospital in which the woman
died, instead of the size of the delivery hospital, was used for
this analysis.

Live-birth order was assessed for women who died after
delivering a live-born infant. Although birth and fetal death
certificates provided information regarding past pregnancy
outcomes, the natality files (used for denominators for ratio
calculations) only provided information regarding live-birth
order.

The assessment of the time interval between delivery and
death was restricted to women who had either a live birth or a
stillbirth because information concerning the interval between
termination of pregnancy and maternal death was not available for
women who died after other pregnancy outcomes or who were
undelivered at the time of death.

All unknown, not stated, or missing information -- which
accounted for less than or equal to 20% of the total for each
variable -- were proportionally redistributed in known categories.

RESULTS

A total of 1,618 potential pregnancy-related deaths were
reported to CDC for 1987-1990. Seven deaths, although causally
related to pregnancy, were excluded from this analysis because the
time period between delivery and death exceeded 1 year. In
addition, the analysis excluded 151 deaths that occurred within 1
year after delivery (i.e., because the causes of death were not
directly related to pregnancy) and one death that was classified
as unknown as to whether the death was linked to a pregnancy. The
remaining 1,459 deaths were used as the basis of this analysis. A
matched birth certificate was available for 95% of deaths
following a live birth, and a matched fetal death certificate was
available for 86% of deaths following a stillbirth.

The number of pregnancy-related deaths and the
pregnancy-related mortality ratios in this analysis differed
slightly from previously published reports (17) because of
subsequently received or updated information. The overall
pregnancy-related mortality ratio for the 4-year surveillance
period was 9.2 deaths per 100,000 live births; the ratio increased
sharply from 1987 (7.2 deaths per 100,000 live births) to 1988
(9.5 per 100,000), and then increased slightly to 10.0 per 100,000
over the following 2 years (Table_1).

Women who were aged greater than or equal to 30 years had a
higher risk for pregnancy-related death than younger women
(Table_2).
Women aged 35-39 years had a 2.6 times higher risk for death
than women aged 25-29 years; this risk increased to 5.9 times
higher for women aged greater than or equal to 40 years.

Race was strongly associated with pregnancy-related
mortality -- particularly for black women, who were almost four
times more likely to die from pregnancy-related causes than were
white women (Table_3). The difference between pregnancy-related
mortality ratios for black women and white women increased from
3.4 in 1987 to 4.1 in 1990. The risk for pregnancy-related
mortality was 1.6 times higher for women of other races than for
white women.

Age-specific pregnancy-related mortality ratios were higher
for black women than for white women at all ages (Figure_1).
The
risk for pregnancy-related death was 10.2 times greater for black
women aged greater than or equal to 40 years than the risk for
black women aged 20-24 years; the risk was 5.0 times greater for
white women aged greater than or equal to 40 years than the risk
for white women aged 20-24 years. In comparison with
pregnancy-related mortality ratios for white women, ratios for
black women increased sharply with age, beginning with women aged
25-29 years. This difference was most pronounced at ages greater
than or equal to 40 years (i.e., the ratio was 6.4 times higher
for black women).

The most common pregnancy outcome associated with a
pregnancy-related death was a live birth (55%), followed by an
ectopic pregnancy (11%), an undelivered pregnancy (7%), or a
stillbirth (7%) (Figure_2). For white women, 58% of
pregnancy-related deaths followed a live birth, compared with 49%
for black women (Table_4). More pregnancy-related deaths
followed
ectopic pregnancies and abortions (spontaneous and induced) among
black women (14% and 7%, respectively) than among white women (8%
and 4%, respectively). In contrast, 70% of deaths among women of
"other" races were associated with a live birth outcome; 7% of
deaths among these women were associated with an ectopic
pregnancy, and 6% were associated with an abortion.

The risk for pregnancy-related death among unmarried women
was almost twice the risk among married women. After adjustment
for age, the pregnancy-related mortality ratio was 18.1 deaths per
100,000 live births for all unmarried women and 7.0 for all
married women (Figure_3). The age-adjusted pregnancy-related
mortality ratio for unmarried white women was 2.1 times greater
than that for married white women (11.6 vs. 5.5 deaths per 100,000
live births), whereas this same ratio for unmarried black women
was 1.3 times greater than that for married black women (29.0 vs.
23.1 deaths per 100,000 live births). For women of "other" races,
the age-adjusted pregnancy-related mortality ratio for unmarried
women differed slightly compared with that for married women (9.2
vs. 8.1 deaths per 100,000 live births).

For all women, the risk for pregnancy-related death following
a live birth or a stillbirth significantly decreased with
increasing levels of education for women aged greater than or
equal to 25 years (Figure_4). The educational level of women
aged
20-24 years did not affect the risk for pregnancy-related death.
Age-specific pregnancy-related mortality ratios for black women
were consistently higher than ratios for white women at all levels
of education. Among white women aged greater than or equal to 25
years, the risk for pregnancy-related death for those who had less
than or equal to 12 years of education was almost twice that for
women who had greater than 12 years of education. Regardless of
educational level, however, the risk for pregnancy-related death
among black women of all ages did not differ significantly.

Of all the women who died following a live birth, 9% had not
received prenatal care. The crude rate of pregnancy-related death
was 7.7 times higher for women who received no prenatal care than
for women who received "adequate" care (Table_5). When adjusted
for gestational age, the rate declined to 6.2 times higher for
women who received no prenatal care than for women who received
"adequate" care (Figure_5). When compared with women who
received
some level of prenatal care, women who received no prenatal care
were more likely to have had four or more previous live births and
to be unmarried and less educated.

After adjustment for gestational age, the risk for
pregnancy-related death was slightly higher for women who received
"inadequate" prenatal care than for women who received "adequate"
care (relative risk {RR}=1.7). In addition, the gestational
age-adjusted risk for pregnancy-related death was 1.8 times higher
for women who received prenatal care categorized as "adequate
plus" than for women who received "adequate" care.

Mortality rates for all categories of prenatal care were
higher for black women and women of other races than for white
women (Table_5). Approximately 8% of white women and 11% of
black
women who died from pregnancy-related causes received no prenatal
care. The risk associated with receiving no prenatal care compared
with receiving "adequate" care was greater for white women
(RR=7.8) and women of other races (RR=12.7) than for black women
(RR=3.7).

Of all women whose pregnancies resulted in a live birth, the
risk for pregnancy-related death increased with increasing
live-birth order, beginning with women delivering their third
live-born infant (Table_6). The mortality rate was
approximately
three times greater for women following delivery of a fifth or
higher-order live-born infant than for women following a second
live birth.

Although few pregnancy-related deaths were reported for
adolescents (i.e., females aged less than 20 years), the risk for
pregnancy-related death was 10-11 times higher for adolescents
following delivery of a fourth live-born infant in comparison with
those delivering a first through third live-born infant.

For both white women and black women, the risk for
pregnancy-related death for women who had a fifth or higher-order
live birth was 2.6 times greater than that for women with the
lowest rate of pregnancy-related death. For white women of all
ages, this risk was lowest following the second live birth; for
black women of all ages, the risk was lowest for women following
the first live birth. Although the risk for death associated with
live-birth order for all women was lowest after delivery of the
second live-born infant, the disparity in the risk for death
between black women and white women after delivery of the second
live-born infant was greater than the risk for any other
live-birth-order category.

The leading causes of death differed by pregnancy outcome
(Table_7). The leading causes of death for women who died after
a
live birth were pregnancy-induced hypertension complications,
pulmonary embolism (mostly thrombotic and amniotic fluid
embolism), hemorrhage (primarily from postpartum atony,
complications from disseminated intravascular coagulation, and
abruptio placentae), and infection. For women whose pregnancies
ended in a stillbirth, the leading causes of death were hemorrhage
(from abruptio placentae and uterine rupture), pregnancy-induced
hypertension complications, and infection. Hemorrhage resulting
from rupture of the ectopic site accounted for almost 95% of
deaths associated with ectopic pregnancies. Among women whose
pregnancies ended in a spontaneous or induced abortion, infection
was the cause of death for almost half of the women; most of the
remaining deaths resulted from hemorrhage, pulmonary embolism, and
anesthesia complications. Women who had molar pregnancies died
from a variety of causes. Women who were still pregnant
(undelivered) at the time of death most frequently died from
thrombotic and amniotic fluid embolism, hemorrhage from abruptio
placentae, and infection.

Hemorrhage was the immediate cause of death for 418 (29%)
women regardless of pregnancy outcome; however, for an additional
83 (6%) women, hemorrhage was an associated condition contributing
to death. Two hundred eighty-eight (20%) women died from pulmonary
embolism; for another 67 (5%) women, embolism was an associated
condition. Pregnancy-induced hypertension was the immediate cause
of death for 257 (18%) women, and it was an associated condition
for an additional 67 (5%) women.

The cause-specific pregnancy-related mortality ratios for all
causes of death were higher for black women than for white women
or women of other races, with hemorrhage, pulmonary embolism, and
pregnancy-induced hypertension the leading causes of death for
each race group. The risk for pregnancy-related death for each
cause of death was approximately three to four times greater for
black women compared with white women. However, the risk for death
as a result of cardiomyopathy and complications of anesthesia was
six to seven times greater for black women than for white women.

The risk for pregnancy-related death was highest for women
who delivered a live-born or stillborn infant in a hospital with
2,000-2,999 live births per year (7.2 deaths per 100,000 live
births) and lowest in hospitals with less than 300 live births per
year (3.3 per 100,000) (Table_8). Cause-specific
pregnancy-related
mortality ratios differed for women by hospital size groups. The
cause-specific pregnancy-related mortality ratios for deaths
resulting from pulmonary embolism were highest for hospitals with
less than 300 live births per year, and the ratios for deaths
resulting from pregnancy-induced hypertension were highest for
hospitals with greater than or equal to 2,000 live births per
year.

Information regarding the specific time interval between
delivery and death was unknown for 38 of the 904 women who died
following a live birth or stillbirth. Of the remaining 866 women,
most (550 {64%}) died within the first week after delivery; more
than half of these deaths occurred within 1 day after delivery
(Figure_6). Overall, 803 (93%) of these deaths occurred within
42
days after delivery. Of the 63 (7%) women who died between 43 days
and 1 year after delivery, 23 (37%) died as a result of
cardiomyopathy, and nine (14%) as a result of pulmonary embolism.
Approximately half of all deaths attributed to cardiomyopathy
during the surveillance period occurred greater than 42 days after
delivery.

DISCUSSION
Trends in Pregnancy-Related Mortality

During 1987-1990, the projected Healthy People 2000 (1) goal
that called for a reduction in maternal mortality was not met
overall or for any racial/ethnic group. After a steady decline in
the reported pregnancy-related mortality ratios from 1979 through
1986 (3), the reported mortality ratios increased from 7.2
pregnancy-related deaths per 100,000 live births in 1987 to 10.0
in 1990. This increase in the pregnancy-related mortality ratio
probably reflected the improved surveillance system and reporting
guidelines initiated in 1988 (8,17).

Race-Specific Disparities

Pregnancy-related mortality ratios continued to be three to
four times higher for black women than for white women (2,3,17).
The risk for pregnancy-related death was consistently higher among
black women than among white women for every factor evaluated by
race in this analysis.

As noted in previously published reports, the risk for death
associated with age differed for black women and white women. The
difference in the risk for death between black women and white
women widened with increasingly older maternal age; the
pregnancy-related mortality ratios for black women aged greater
than or equal to 35 years were particularly high in comparison
with white women in the same age group (3,18). Higher levels of
education were associated with decreased pregnancy-related
mortality ratios among white women; however, among black women,
the risk for pregnancy-related death did not differ significantly
by educational level (3,4). Although the risk for
pregnancy-related death was higher among unmarried white women
than among married white women, marital status was not a
significant factor in the risk for pregnancy-related death among
black women and women of other races (19). Although the risk for
pregnancy-related death among white women was lowest for those
delivering their second live-born infant, the greatest difference
between black women and white women in the risk for death occurred
among women delivering their second live-born infant.

Pregnancy-related mortality rates for women of black and
other races were higher at all levels of prenatal care than rates
for white women. The reduction in mortality rates for women who
received prenatal care compared with women who received no
prenatal care was greater among white women than among black
women. The results of several studies have suggested that the
content of prenatal care might differ for black women and white
women (20-22). Furthermore, even though more intensive monitoring
is recommended during late pregnancy (i.e., the eighth and ninth
months of gestation) (16,23), black women make fewer prenatal-care
visits during this time period than do white women (24).
Researchers have determined that black women, in comparison with
white women, often receive fewer services and insufficient
health-promotion education during their prenatal visits (21,25).

The proportion of pregnancy-related deaths associated with
ectopic pregnancy or abortion (spontaneous and induced) was
greater among black women than among white women. The risk
associated with most causes of pregnancy-related death was
approximately three to four times higher for black women than for
white women; the risk for pregnancy-related death resulting from
cardiomyopathy and complications of anesthesia both were more than
six times higher for black women than for white women.

The risk factors evaluated in this surveillance system
confirmed the race-specific differences in pregnancy-related
death, but the reasons for the disparities could not be determined
from the available information. Factors other than race alone --
probably factors not measurable through routine surveillance --
most
likely played an important role in contributing to the increased
risk for pregnancy-related death among black women. It remains
unclear whether the racial disparity might be related to
differences in the seriousness of morbidity, differences in
co-existing risk factors or other conditions, differences in
diagnosis and treatment of pregnancy-related complications, or
some combination of all these factors. Some researchers have
suggested that race may serve as a marker for other
sociodemographic risk factors and cultural differences (26,27).
The sources from which data were obtained for this surveillance
system did not provide information concerning socioeconomic
indices, family and community conditions, and other factors that
might be associated with the differences in pregnancy-related
mortality between black women and white women.

Age

As reported previously, older women were at increased risk
for pregnancy-related death (3,17). Women aged greater than or
equal to 40 years had six times the risk for pregnancy-related
death in comparison with women aged 25-29 years. The risks for
both chronic disease and complications of pregnancy increase with
age; women aged greater than or equal to 35 years are at greater
risk than younger women for many adverse reproductive health
outcomes, including pregnancy-related mortality (18,28).

Education

Overall, women with a limited education were at higher risk
for pregnancy-related death than women with more education, a
finding consistent with previous studies (3,4). The risk for
pregnancy-related death among women who had less than a high
school education was much greater for older women than younger
women.

Prenatal Care

High-quality prenatal-care services can prevent or identify
problems and complications that arise during pregnancy, labor and
delivery, and the postpartum period (23). The absence of prenatal
care should be regarded as a sentinel health event (29). Although
it has been suggested that assessing prenatal care by a measure of
the content and quality is preferable to measuring the quantity of
care and the timing of visits (30), the modified APCU index used
in this analysis did not evaluate the content or quality of care,
and the sources of information (i.e., the vital records) did not
provide information that would enable such an assessment.

In comparison with all women who delivered a live-born infant
during 1987-1990, a greater proportion of women who died from
pregnancy-related causes after delivering a live-born infant had
received no prenatal care (9% vs. 2%, respectively) (9-12). Women
who received any level of prenatal care had a lower risk for
pregnancy-related mortality in comparison with women who received
no prenatal care. In this analysis and in other previously
published reports, women who received no prenatal care were more
likely to be older, black, and unmarried; to have a higher number
of live-born infants (i.e., four or more births); and to be less
educated than women who had pre-natal care, including women who
initiated such care during the third trimester of pregnancy (31).
In addition to an elevated risk for pregnancy-related death among
women who received no prenatal care, the risk for death was higher
among women whose prenatal care was categorized as "adequate plus"
than among women who received "adequate" care. Previous studies
have indicated that women who receive more than the recommended
number of prenatal visits are more likely to be at "high risk" and
to have complicated medical conditions and/or pregnancy
complications that could contribute to an increased risk for
pregnancy-related death (3,15).

Causes of Death

This surveillance system and previous reports (19,32)
identified the same leading causes of pregnancy-related death:
hemorrhage, pulmonary embolism, and pregnancy-induced hypertension
complications. Pregnancy-induced hypertension and pulmonary
embolism accounted for the greatest number of deaths among both
white women and black women who delivered a live-born infant.

Hospital Size

In contrast with a study that indicated the risk for
pregnancy-related death was highest in the smallest (i.e., less
than or equal to 300 deliveries per year) and largest hospitals
(i.e., greater than or equal to 3,001 deliveries per year) (32),
the analysis of pregnancy-related mortality surveillance data for
1987-1990 indicated that women who delivered at the smallest
hospitals had the lowest pregnancy-related mortality ratio.
However, women who died after delivery at the smallest hospitals
also had the highest pregnancy-related mortality ratio associated
with pulmonary embolism. The diagnosis and management of pulmonary
embolism in the pregnant woman or recently pregnant woman is
complex, and resources for its diagnosis and treatment may not be
readily available at small hospitals (33).

Data Limitations

Although this analysis examined the various risk factors for
pregnancy-related mortality during 1987-1990, several limitations
of the analysis should be considered. Pregnancy-related death
encompasses a complex combination of etiologies and pregnancy
outcomes, and the underlying risk factors associated with death
might vary with cause of death and/or pregnancy outcome. Even
though the availability of matched birth and fetal death records
improved the quality and quantity of the available information,
the assessment of the pathophysiology and circumstances leading to
pregnancy-related death and the determination of associated risk
factors were limited by the absence of detailed clinical
information.

Despite improved ascertainment methods by some states during
the surveillance period, greater than 50% of pregnancy-related
deaths possibly were misclassified and were, therefore, undetected
by routine surveillance methods (34-36). Because a mention of
pregnancy or recent pregnancy is not always included on a woman's
death certificate, some states have established a system whereby
information contained in the vital records links the records of
deaths of reproductive-aged women with records of concomitant live
births and stillbirths. This process improves ascertainment of
pregnancy-related deaths associated with live-birth or fetal-death
outcomes. However, linkage of vital records does not identify
pregnancy-related deaths that do not generate a record of
pregnancy outcome (37). Such records include deaths resulting from
ectopic pregnancies, deaths associated with spontaneous and
induced abortion, and deaths that occur during pregnancy before
delivery. Most pregnancy-related deaths were identified and
classified by using routine information on vital records;
therefore, the numbers and ratios understate the actual number of
pregnancy-related deaths that occurred during the surveillance
period (38).

Public Health Measures

Ascertainment of pregnancy-related deaths can be improved by
computerized linkage of death certificates of reproductive-aged
women with birth and fetal death certificates, pregnancy check
boxes on death certificates, periodic review of deaths of
reproductive-aged women, and ongoing birth registries and medical
audits (38,39). Additional sources of data, including family
interviews, may be necessary to understand the effects of
socioeconomic status, access to and content of prenatal care, and
social environment and lifestyle on the sequence of events that
lead to pregnancy-related deaths. The continuing disparity in
pregnancy-related mortality between white women and black women
emphasizes the need to identify those differences that contribute
to excess mortality among black women. Specific interventions
should be developed to reduce pregnancy-related mortality among
black women. Improved surveillance and additional research are
needed to assess the magnitude of pregnancy-related deaths,
further identify potential risk groups, and provide information
that policy makers can use to develop effective strategies to
prevent pregnancy-related mortality for all women.

Public Health Service Expert Panel on the Content of Prenatal
Care. Caring for our future: the content of prenatal care.
Washington, DC: US Department of Health and Human Services,
Public
Health Service, 1989.

Elam-Evans LD, Adams MM, Gargiullo PM, Kiely JL, Marks JS.
Trends in the percentage of women who received no prenatal care
in
the United States, 1980-1992: contributions of the demographic
and
risk effects. Obstet Gynecol 1996;87:575-80.

Elam-Evans LD, Adams MM, Gargiullo PM, Kiely JL. Heterogeneity
between women who received prenatal care in the third trimester
and those who received no prenatal care. J Am Med Wom Assoc
1995;50:175-7.

Table_5Note: To print large tables and graphs users may have to change their printer settings to landscape and use a small font size.

TABLE 5. Crude pregnancy-related mortality rate, * by race + and
adequacy of prenatal care & -- United States,@ 1987-1990
======================================================================
Race
Adequacy of --------------------------
prenatal care White Black Other ** All deaths
----------------------------------------------------------------------
No care 19.0 26.5 49.5 ++ 23.0
Inadequate 3.3 10.3 6.6 5.0
Adequate 2.4 7.0 3.7 3.0
Adequate plus 5.5 14.8 10.7 7.3
All levels of care 3.6 11.2 7.1 5.1
----------------------------------------------------------------------
* Pregnancy-related deaths among women who delivered a live-born
infant per 100,000 live births.
+ Hispanic women were classified by their reported racial group.
Levels of prenatal care were based on a modification of the
adequacy of prenatal care use (APCU) index developed by Kotelchuck
( 15 ), and they were defined as follows: adequate plus -- care
began at <=4 months of pregnancy, and >=110% of recommended
prenatal care visits were made (i.e., in accordance with standards
established by the American College of Obstetricians and
Gynecologists); adequate -- care began at <=4 months of pregnancy,
and 80%-90% of recommended visits were made; inadequate -- care
began at <=4 months of pregnancy, and <80% of recommended visits
were made, or care began at 35 months of pregnancy (recommended
number of visits not applicable); and no care -- no prenatal
care obtained.
& Excludes California for 1987-1988.
** Includes Asian/Pacific Islander, American Indian/Alaskan
Native, and those reported as "other."
++ This rate was based on fewer than five deaths and should be
interpreted with caution.
======================================================================

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